Putting an image with your for sale ad will surely make all the difference in selling and here's how to do it:
If you already have the image on the internet then simple click the image button as shown in the picture below when you are making a post:
Then type the link (or copy/paste the link) into the field provided and click ok.
If you want to insert a picture into your post from your computer then you need to click the 'host image' button which is shown in the picture below:
Once you click this you simply select the image from your computer by clicking browse. Then click the 'host it' button. You will now see 3 links, you need to click the 'copy' button on the third link (which is name image url). Then you simply click the image button as described earlier and paste the link into there and click ok. Job done
You do not need to worry about the size of the image the site will automatically scale the size to fit into your post with the option to click it to see the original size if needed.